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How to Estimate Wattage Requirements

The flow of electrical current is the basis of modern technological devices, and there are a number of specific quantities that are important in device design. Voltage is defined as the potential energy per unit charge, and is essentially a measure of the energy that electrons have within a circuit. Current is a scaled measure of electron velocity and is very important in all electrical applications. When designing an electrical device, it̵7;s important to consider the power (wattage) requirements, which are dependent upon both the voltage and current in the circuit.

Things You'll Need

Calculator
Multimeter

Instructions

- 1
  Look up the specification current of the device. Electrical devices come with a specification sheet that states the maximum current that can be placed through the device.
- 2
  Switch the multimeter to resistance mode. Place the measurement probes across the device whose wattage requirements are needed. Take a note of the resistance value measured. Resistance is measured in ohms.
- 3
  Calculate the voltage needed using Ohm's law. Ohm`s law states: ̶0;V = IR.̶1; ̶0;I̶1; is the current and ̶0;R̶1; is the resistance.
- 4
  Calculate the power (wattage) of the device. The power can be calculated using the following equation: ̶0;P = IV.̶1; Power is measured in Watts, thus the wattage requirements have been calculated.

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